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algorithm: freeSockets pop/shift #8
Description
the current algorithm maximize the number of sockets opened, by re-using the first stacked free socket using freesockets.shift()
@see https://github.com/node-modules/agentkeepalive/blob/master/lib/_http_agent.js#L170
if (freeLen) {
// we have a free socket, so use that.
var socket = this.freeSockets[name].shift();
debug('have free socket');freesockets = [1][2][3][4][5]
# a socket is freed
freesockets = [1][2][3][4][5][6]
# new request arrive, current algorithm use "shift"
freesockets = [2][3][4][5][6]
# there might rarely be a timeout of any sockets.
an alternative could be to use freesockets.pop() to minimize the number of sockets opened
freesockets = [1][2][3][4][5]
# a socket is freed
freesockets = [1][2][3][4][5][6]
# new request arrive, using pop
freesockets = [1][2][3][4][5]
# first socket timeout
freesockets = [2][3][4][5]
implementation:
var algo = (this.options.algo === 'pop') ? 'pop' : 'shift';
var socket = this.freeSockets[name][algo]();I tested this for 1K request/s, it divided the pool size by 5.
Activity
fengmk2 commentedon Sep 2, 2014
@syndr0m good point! Can you impl this with a pr?
FredKSchott commentedon Oct 27, 2014
@syndr0m this sounds awesome!
fengmk2 commentedon Jan 29, 2015
Any progress?
fengmk2 commentedon Jan 29, 2015
I think use pop instead of shift is enough
tony-gutierrez commentedon Oct 20, 2018
Did this ever happen?
bfdill commentedon Mar 15, 2019
fyi, the referenced code is not currently in this project:
https://github.com/nodejs/node/blob/master/lib/_http_agent.js#L165
You'd probably need to replace addRequest and curry the selected algorithm into the original'ish version.
A quick thought here... While it would be nice to be able to have the algorithm choice, I believe the intended behavior of keep-alives is to keep connections alive to reduce the overhead of establishing connections. The max number of free connections is configurable, so I'm not sure if this functionality has a ton of value.
dkMorlok commentedon Jun 27, 2020
Maybe related/solved by this nodejs/node#33278 ?